Molten air could increase capacity, reduce weight in battery technology

With energy storage becoming increasingly important for the adoption of renewable energy sources, creating more efficient, longer lasting, and higher capacity batteries than we currently have is taking precedence. A team led by George Washington University Chemist Stuart Licht is doing just that.

A new class of rechargeable batteries – 'molten air' batteries – solve these challenges by using highly conductive molten electrolytes and very high capacity multiple electron compounds such as carbon and vanadium diboride (VB2). Unlike prior rechargeable molten batteries, the molten air battery is not burdened by the weight of the active chargeable cathode material. The rechargeable molten air electrode instead uses oxygen directly from the air to yield high battery capacity.

"Molten air batteries advance the field of energy storage by opening up multiple opportunities for new higher capacity batteries," Stuart Licht , a professor of chemistry at George Washington University, tells Nanowerk. "These are the first batteries to reversibly use oxygen from the air to store energy via a molten salt and multiple electrons stored per molecule at the counter electrode."

While still experimental, the technique they are using, which is explained in the paper they published in an online edition of Energy & Environmental Science, is a proof of concept could lead to many different applications, both large and small scale.

Potential applications of these molten air batteries could be large scale energy storage for electric grids (for example to store electricity when wind or solar electric is not available); higher storage capacity for electric cars (for example this system has much greater capacity than high temperature sodium sulfur batteries which had been previously investigated); or higher storage capacity for drones.